Laser system for dicing semiconductor structure and operation method thereof

ABSTRACT

A laser system for dicing a semiconductor structure is disclosed. The laser system includes a laser source and a laser energy adjusting unit. The laser source is configured to generate a laser. The laser energy adjusting unit is movably provided on a laser light path between the laser source and the semiconductor structure. The laser energy adjusting unit is moved to the laser light path between the laser source and the semiconductor structure based on a first determination that the laser source is focused on a first preset region of the semiconductor structure having a first material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation of International Application No.PCT/CN2021/084445, filed on Mar. 31, 2021, entitled “LASER SYSTEM FORDICING SEMICONDUCTOR STRUCTURE AND OPERATION METHOD THEREOF,” which ishereby incorporated by reference in its entirety. This application isalso related to co-pending U.S. application Ser. No. ______, AttorneyDocketing No.: 10018-01-0217-US, filed on even date, entitled “LASERDICING SYSTEM AND METHOD FOR DICING SEMICONDUCTOR STRUCTURE,” which ishereby incorporated by reference in its entirety.

BACKGROUND

The present disclosure relates to laser systems for dicing asemiconductor structure and operation methods thereof.

In semiconductor manufacturing, wafers or semiconductor structures arediced to separate dies that form integrated circuits. Common ways todice wafers include mechanical sawing and laser dicing. The mechanicalsawing methods often include employing a dicing saw to mechanicallyseparate different dies in a wafer. The laser dicing methods ofteninclude directing the output of an ultra-short and pulsed high-powerlaser through optics. The mechanical sawing and the laser dicing mayalso be combined to separate dies. A dicing process can produceindividual circuit chips that are further packaged to form desiredcircuits.

SUMMARY

Laser systems for dicing a semiconductor structure and operation methodsare disclosed herein.

In one aspect, a laser system for dicing a semiconductor structure isdisclosed. The laser system includes a laser source and a laser energyadjusting unit. The laser source is configured to generate laser. Thelaser energy adjusting unit is movably provided on a laser light pathbetween the laser source and the semiconductor structure. The laserenergy adjusting unit is moved to the laser light path between the lasersource and the semiconductor structure based on a first determinationthat the laser source is focused on a first preset region of thesemiconductor structure having a first material.

In another aspect, a laser system for dicing a semiconductor structureis disclosed. The laser system includes a laser source, a splitter, anda laser energy adjusting unit. The laser source is configured togenerate laser. The splitter splits the laser source into a plurality ofsplit laser sources, and the plurality of split laser sources include afirst split laser source and a second split laser source. The laserenergy adjusting unit is movably provided on a first laser light pathbetween the first split laser source and the semiconductor structure.The first split laser source generates a first dicing energy irradiatedon the semiconductor structure along a first track, the second splitlaser source generates a second dicing energy irradiated on thesemiconductor structure along a second track parallel to the firsttrack, and the first track and the second track are located in a cuttingstreet. The first dicing energy irradiated on the semiconductorstructure along the first track is adjustable.

In still another aspect, a method for dicing a wafer is disclosed. Atrench is formed on the wafer by a laser source along a cutting street.An output energy of the laser source maintains the same when dicing thewafer along the cutting street, and a dicing energy irradiated on thewafer is adjustable when dicing the wafer along the cutting street. Amechanical cutting is performed on the wafer along the cutting streethaving the trench formed by the laser source.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and form a partof the specification, illustrate aspects of the present disclosure and,together with the description, further serve to explain the presentdisclosure and to enable a person skilled in the pertinent art to makeand use the present disclosure.

FIG. 1 illustrates a schematic diagram of an exemplary laser system fordicing a semiconductor structure, according to some implementations ofthe present disclosure.

FIG. 2 illustrates a top view of an exemplary cutting street formed on asemiconductor structure, according to some implementations of thepresent disclosure.

FIG. 3 illustrates a cross-section of an exemplary cutting street formedon a semiconductor structure, according to some implementations of thepresent disclosure.

FIG. 4 illustrates a scanning electron microscope image showing across-section of an exemplary cutting street formed on a semiconductorstructure, according to some implementations of the present disclosure.

FIG. 5 illustrates a diagram of another exemplary laser system fordicing a semiconductor structure, according to some implementations ofthe present disclosure.

FIG. 6 illustrates a top view of an exemplary cutting street formed on asemiconductor structure, according to some implementations of thepresent disclosure.

FIG. 7 illustrates a diagram of still another exemplary laser system fordicing a semiconductor structure, according to some implementations ofthe present disclosure.

FIG. 8 illustrates a top view of an exemplary cutting street formed on asemiconductor structure, according to some implementations of thepresent disclosure.

FIG. 9 illustrates a flowchart of a method for dicing a wafer, accordingto some aspects of the present disclosure.

FIG. 10 illustrates a schematic diagram of an exemplary host device,according to some implementations of the present disclosure.

The present disclosure will be described with reference to theaccompanying drawings.

DETAILED DESCRIPTION

Although specific configurations and arrangements are discussed, itshould be understood that this is done for illustrative purposes only.As such, other configurations and arrangements can be used withoutdeparting from the scope of the present disclosure. Also, the presentdisclosure can also be employed in a variety of other applications.Functional and structural features as described in the presentdisclosures can be combined, adjusted, and modified with one another andin ways not specifically depicted in the drawings, such that thesecombinations, adjustments, and modifications are within the scope of thepresent discloses.

In general, terminology may be understood at least in part from usage incontext. For example, the term “one or more” as used herein, dependingat least in part upon context, may be used to describe any feature,structure, or characteristic in a singular sense or may be used todescribe combinations of features, structures or characteristics in aplural sense. Similarly, terms, such as “a,” “an,” or “the,” again, maybe understood to convey a singular usage or to convey a plural usage,depending at least in part upon context. In addition, the term “basedon” may be understood as not necessarily intended to convey an exclusiveset of factors and may, instead, allow for existence of additionalfactors not necessarily expressly described, again, depending at leastin part on context.

The laser grooving process is performed to remove the metal or othercomplex materials on the cutting street, or called cutting channel, andensure the consistency of the physical cutting environment of asubsequent mechanical cutting. The laser grooving process could reducethe reliability problems caused by chip collapse and improve thepackaging yield of the integrated circuits.

FIG. 1 illustrates a schematic diagram of an exemplary laser system 100for dicing a semiconductor structure 102, according to someimplementations of the present disclosure. Laser system 100 includes alaser source 104 and a focusing unit 108. Laser source 104 may be anysuitable type of laser source including, but not limited to, fiberlasers, solid-state lasers, gas lasers, and semiconductor lasers. Lasersource 104 can be configured to generate a laser beam 106 that includesone or a series of pulsed lasers at any suitable wavelengths, whichshould be a permeable wavelength not strongly absorbed or reflected bysemiconductor structure 102. In the case of silicon wafer cutting, thewavelength may be longer than 1 μm to realize the internal laserablation, making full use of the laser energy and avoiding any damage tothe upper part of the wafer when a focused laser beam creates a dicingtrack inside semiconductor structure 102.

In some implementations, laser beam 106 generated by laser source 104may have a single wavelength or a plurality of wavelengths, such as twoor three different wavelengths. Laser beam 106 having differentwavelengths may be separately, simultaneously, or alternatinglygenerated. In some implementations, the wavelength of the laser beam 106generated by laser source 104 may be longer than 1 μm. In someimplementations, the output frequency of laser source 104 is between 10kHz and 1,000 kHz. In some implementations, the average output power oflaser source 104 is between 5 W and 500 W. It is understood that theparameters of laser beam 106 and laser source 104 disclosed above arefor illustrative purposes only and not for limiting.

Focusing unit 108 may be optically coupled to laser source 104 toprovide a series of focused laser spots on semiconductor structure 102based on the series of pulsed lasers generated by laser source 104. Forexample, the series of pulsed lasers can form a series of focused laserspots at a horizontal location on a focal plane. In someimplementations, focusing unit 108 may be operatively coupled to acontroller and receives control signals and instructions from thecontroller. In some implementations, focusing unit 108 may furtherinclude any other suitable scanning units, scanning mirrors, andscanning refractive optics.

Focusing unit 108 may be configured to focus each of the laser beam 106to form a series of focused laser spots. In some implementations,focusing unit 108 may include one or more focusing lens through whichthe focal plane of the laser beam 106 is determined at a desiredposition along the z-axis (e.g., the vertical direction). In someimplementations, the one or more focusing lenses are electrically andmechanically coupled to the controller to control the arrangement (e.g.,orientation and distance in between) of the one or more focusing lens toallow the focal plane of laser beam 106 to be located at the desiredposition along the z-axis. The series of focused laser spots can beformed on the focal plane, forming ablation structures 110 insemiconductor structure 102.

In some implementations, a dimension of each of the focused laser spotsis between 0.2 μm and 5 μm, such as 0.2 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4μm, 5 μm, any range bounded by the lower end by any of these values, orin any range defined by any two of these values. The shape of eachfocused laser spot can include, for example, round, rectangle, square,irregular, or any suitable shapes. In some implementations, each focusedlaser spot has a substantially round shape with a diameter between 1 μmand 5 μm. It is understood that the dimensions of a series of focusedlaser spots can be substantially the same or different. By focusing thebeams of laser beam 106 into focused laser spots, the energy density canbe significantly increased.

FIG. 2 illustrates a top view 200 of an exemplary cutting street 204formed on a semiconductor structure 202, according to someimplementations of the present disclosure. FIG. 3 illustrates across-section 300 of cutting street 204 formed on semiconductorstructure 202, according to some implementations of the presentdisclosure. For the purpose of better explaining the present disclosure,top view 200 of cutting street 204 in FIG. 2 and cross-section 300 ofcutting street 204 in FIG. 3 will be described together. In someimplementations, semiconductor structure 202 may be a wafer. In someimplementations, the chips on semiconductor structure 202 are surroundedby seal rings 206, and cutting street 204 is used to dice semiconductorstructure 202 without damaging seal rings 206. In some implementations,seal rings 206 may include metal materials.

When performing the laser dicing, a plurality of laser sources maygenerate a plurality of dicing laser energy, and the dicing energy maybe irradiated on semiconductor structure 202 sequentially. As shown inFIG. 2, a laser dicing track 208 may include a plurality of laser tracksperformed by a plurality of laser sources sequentially. It is understoodthat the plurality of laser sources may be applied simultaneously onsemiconductor structure 202 based on different designs of the dicingsystem. By controlling the movement of laser source 104 and focusingunit 108 in FIG. 1, laser dicing track 208 may be limited in the rangeof cutting street 204 without damaging seal rings 206.

In some implementations, laser dicing track 208 may be formed by lasertracks 302, 304, 306, 308, and 310, as shown in FIG. 3. In someimplementations, laser tracks 302 and 304 may be formed by two lasersources having the same energy. In some implementations, laser tracks302 and 304 may be formed by two laser sources having differentenergies. In some implementations, laser tracks 302 and 304 may beformed by a same laser source sequentially. In some implementations,laser tracks 302 and 304 may be formed by a same laser sourcesimultaneously. In some implementations, laser tracks 302 and 304 may beformed by a same laser source split by a splitter simultaneously. Insome implementations, laser tracks 306 and 308 may be formed by twolaser sources having the same energy. In some implementations, lasertracks 306 and 308 may be formed by two laser sources having differentenergies. In some implementations, laser tracks 306 and 308 may beformed by a same laser source sequentially. In some implementations,laser tracks 306 and 308 may be formed by a same laser sourcesimultaneously. In some implementations, laser tracks 306 and 308 may beformed by a same laser source split by a splitter simultaneously.

In some implementations, laser track 310 is deeper than laser tracks 306and 308. In some implementations, laser tracks 306 and 308 are deeperthan laser tracks 302 and 304. As shown in FIG. 3, the combination ofthe plurality of laser tracks 302, 304, 306, 308, and 310 forms atrench, and the mechanical cutting may be later performed onsemiconductor structure 202 along the cutting street having the trench.

FIG. 4 illustrates a scanning electron microscope image 400 showing across-section of cutting street 204 formed on semiconductor structure202, according to some implementations of the present disclosure. Due tothe materials formed on different positions of semiconductor structure202 are various, cutting street 204 may extend along a line havingdifferent materials. For example, semiconductor structure 202 is awafer, and cutting street 204 may cross a plurality of areas havingdifferent metal material, different dielectric materials, or othermaterials. When using laser source 104 to perform the laser dicing,cutting street 204 may have different depths or rough profiles.

A cross-section 402 along line A across cutting street 204 and across-section 404 along line B across cutting street 204 are shown inFIG. 4. Line A across cutting street 204 may be located at a positionhaving hard metal material or having several different metal materials,and line B across cutting street 204 may be located at a position havingsoft metal material or non-metal materials. As shown in FIG. 4,cross-section 402 has a rough profile, and the depth of cross-section402 is shallower than the depth of cross-section 404.

FIG. 5 illustrates a diagram of a laser system 500 for dicing asemiconductor structure 502, according to some implementations of thepresent disclosure. Laser system 500 includes a laser source 504, alaser energy adjusting unit 510, a positioning unit 512, and a focusingunit 508. Laser source 504 may be any suitable type of laser sourceincluding, but not limited to, fiber lasers, solid-state lasers, gaslasers, and semiconductor lasers. Laser source 504 can be configured togenerate a laser beam 506 that includes a series of pulsed lasers at anysuitable wavelengths, which should be a permeable wavelength notstrongly absorbed or reflected by semiconductor structure 502.

Laser energy adjusting unit 510 may be movably provided on a laser lightpath between laser source 504 and the semiconductor structure 502. Laserenergy adjusting unit 510 is provided to reduce or weaken the laserenergy on the laser path. In some implementations, laser energyadjusting unit 510 may be a filter capable of reducing the laser energyoutput by laser source 504 and irradiated on semiconductor structure502. In some implementations, laser energy adjusting unit 510 may be aplurality of filters, and the filters may be provided separately ortogether to generate a gradient transitional dicing energy irradiated onsemiconductor structure 502. In some implementations, laser energyadjusting unit 510 may be an optical device providing an additionallaser light path. By providing the additional laser light path, thelaser light path between laser source 504 and the semiconductorstructure 502 is extended. In a situation that the laser energy outputby laser source 504 is the same, the total laser light path betweenlaser source 504 and the semiconductor structure 502 is extended, andtherefore the laser energy irradiated on semiconductor structure 502 isweakened. In some implementations, laser energy adjusting unit 510 maybe a shelter, e.g., a mask or an optical grate, that may block a portionof laser beam 506 to weaken the laser energy irradiated on semiconductorstructure 502.

Positioning unit 512 is configured to move laser energy adjusting unit510 to the laser light path or move laser energy adjusting unit 510 awayfrom the laser light path. In some implementations, positioning unit 512may be a motor rotationally moving laser energy adjusting unit 510 to oraway from the laser light path. In some implementations, positioningunit 512 may be a shutter mechanism slidably moving laser energyadjusting unit 510 to or away from the laser light path.

Focusing unit 508 may be configured to focus laser beam 506 to form aseries of focused laser spots. In some implementations, focusing unit508 may include one or more focusing lens through which the focal planeof the laser beam 506 is determined at a desired position along thez-axis (e.g., the vertical direction). In some implementations, the oneor more focusing lenses are electrically and mechanically coupled to thecontroller to control the arrangement (e.g., orientation and distance inbetween) of the one or more focusing lens to allow the focal plane oflaser beam 506 to be located at the desired position along the z-axis.The series of focused laser spots can be formed on the focal plane,forming dicing trenches in semiconductor structure 502.

FIG. 6 illustrates a top view of a cutting street 602 formed onsemiconductor structure 502, according to some implementations of thepresent disclosure. In some implementations, the materials ofsemiconductor structure 502 corresponding to positions along cuttingstreet 602 may be pre-defined and stored in a database or a host devicecoupled to the laser system. In some implementations, the materials ofsemiconductor structure 502 corresponding to positions along cuttingstreet 602 may be pre-marked on the semiconductor structure 502, and thelaser system may identify the markings.

When laser system 500 moves along cutting street 602 to perform thelaser dicing operation, one or more laser energy adjusting unit 510 maybe optionally moved to the laser light path between laser source 504 andsemiconductor structure 502 according to the information of thematerials of semiconductor structure 502 corresponding to positionsalong cutting street 602.

In some implementations, laser system 500 may include multiple laserenergy adjusting units 510 corresponding to the treatments of differentmaterials on different regions of semiconductor structure 502. In someimplementations, multiple laser energy adjusting units 510 may includelenses or prisms of different light transmittances. Semiconductorstructure 502 may include a plurality of regions formed by a pluralityof materials, and one of a plurality of laser energy adjusting units 510may be moved to the laser light path between laser source 504 andsemiconductor structure 502 based on the determination that the lasersource is focused on a preset region of semiconductor structure 502.

For example, in some implementations, when the information stored in thedatabase or shown by the markings on semiconductor structure 502indicates that the material corresponding to a position 604 is aless-metal material, a first laser energy adjusting unit may be moved tothe laser light path between laser source 504 and semiconductorstructure 502 to reduce the laser energy output by laser source 504. Asa result, a dicing energy 610 irradiated on semiconductor structure 502is a first laser energy.

In some implementations, when the information stored in the database orshown by the markings on semiconductor structure 502 indicates that thematerial corresponding to a position 606 is a more-metal material, laserenergy adjusting unit 510 may be moved away from the laser light pathbetween laser source 504 and semiconductor structure 502. As a result, adicing energy 612 irradiated on semiconductor structure 502 is theoriginal laser energy output by laser source 504 without weakening andis a second laser energy higher than the first laser energy.

In some implementations, when the information stored in the database orshown by the markings on semiconductor structure 502 indicates that thematerial corresponding to a position 608 is a less-metal material, asecond laser energy adjusting unit may be moved to the laser light pathbetween laser source 504 and semiconductor structure 502 to reduce thelaser energy output by laser source 504. As a result, a dicing energy614 irradiated on semiconductor structure 502 is a third laser energylower than the first energy.

The implementations shown in FIG. 6 illustrate the adjustment along thedirection of cutting street 602 (x-axis). However, it is understood thatthe adjustment of the laser energy may also be applied to differentlaser passes (as shown in FIG. 3) along the y-axis, as shown in FIG. 7.FIG. 7 illustrates a diagram of a laser system 700 for dicing asemiconductor structure 702, according to some implementations of thepresent disclosure.

Laser system 700 includes a laser source 704, a splitter 720, a laserenergy adjusting unit 710, a positioning unit 712, a first focusing unit708, and a second focusing unit 718. Laser source 704 may be anysuitable type of laser source including, but not limited to, fiberlasers, solid-state lasers, gas lasers, and semiconductor lasers. Lasersource 704 can be configured to generate a laser beam 706 that includesa series of pulsed lasers at any suitable wavelengths, which should be apermeable wavelength not strongly absorbed or reflected by semiconductorstructure 702.

Splitter 720 splits laser beam 706 into a first split laser beam 714 anda second split laser beam 716. Splitter 720 may include an opticaldevice that splits laser beam 706 into two or more than two. In someimplementations, splitter 720 may be a cube made from glass prisms. Insome implementations, splitter 720 may be a half-silvered mirror havinga metallic coating or a dichroic optical coating. In someimplementations, splitter 720 may be a dichroic mirrored prism. In someimplementations, first split laser beam 714 and second split laser beam716 may have the same laser energy.

Laser energy adjusting unit 710 may be movably provided on a first laserlight path between splitter 720 and the semiconductor structure 702.Laser energy adjusting unit 710 is provided to reduce or weaken thelaser energy on the first laser path. In some implementations, laserenergy adjusting unit 710 may be a filter capable of reducing the laserenergy of first split laser beam 714 by splitter 720 and irradiated onsemiconductor structure 702. In some implementations, laser energyadjusting unit 710 may be a plurality of filters, and the filters may beprovided separately or together to generate a gradient transitionaldicing energy irradiated on semiconductor structure 702. In someimplementations, laser energy adjusting unit 710 may be an opticaldevice providing an additional laser light path. By providing theadditional laser light path, the first laser light path between splitter720 and the semiconductor structure 702 is extended. In a situation thatthe laser energy of laser beam 714 is the same, the total first laserlight path between splitter 720 and the semiconductor structure 702 isextended, and therefore a first dicing energy irradiated onsemiconductor structure 702 is weakened. In some implementations, laserenergy adjusting unit 710 may be a shelter, e.g., a mask or an opticalgrate, that may block a portion of laser beam 714 to weaken the firstdicing energy irradiated on semiconductor structure 702.

Positioning unit 712 is configured to move laser energy adjusting unit710 to the first laser light path or move laser energy adjusting unit710 away from the first laser light path. In some implementations,positioning unit 712 may be a motor rotationally moving laser energyadjusting unit 710 to or away from the first laser light path. In someimplementations, positioning unit 712 may be a shutter mechanismslidably moving laser energy adjusting unit 710 to or away from thefirst laser light path.

Focusing units 708 and 718 may be configured to focus first split laserbeam 714 and second split laser beam 716 to form a series of focusedlaser spots. In some implementations, focusing unit 708 or 718 mayinclude one or more focusing lens through which the focal plane of firstsplit laser beam 714 and second split laser beam 716 is determined at adesired position along the z-axis (e.g., the vertical direction). Insome implementations, the one or more focusing lenses are electricallyand mechanically coupled to the controller to control the arrangement(e.g., orientation and distance in between) of the one or more focusinglens to allow the focal plane of first split laser beam 714 and secondsplit laser beam 716 to be located at the desired position along thez-axis. The series of focused laser spots can be formed on the focalplane, forming dicing trenches in semiconductor structure 702.

FIG. 8 illustrates a top view 800 of a cutting street 802 formed onsemiconductor structure 702, according to some implementations of thepresent disclosure. A first trench 804 is formed by first split laserbeam 714, and a second trench 806 is formed by second split laser beam716. Since second split laser beam 716 generates the second dicingenergy and the second dicing energy is irradiated on semiconductorstructure 702 without laser energy adjusting unit 710, trench 806 isform by the same second dicing energy. In other words, when laser system700 moves along cutting street 802 to perform the laser dicingoperation, the second dicing energy of second split laser beam 716 onsemiconductor structure 702 along a second track of trench 806 is fixed.

When laser system 700 moves along cutting street 802 to perform thelaser dicing operation, one or more laser energy adjusting unit 710 maybe optionally moved to the first laser light path between splitter 720and semiconductor structure 702 according to the information of thematerials of semiconductor structure 702 corresponding to positionsalong cutting street 802.

In some implementations, laser system 700 may include multiple laserenergy adjusting units 710 corresponding to the treatments of differentmaterials on different regions of semiconductor structure 702. In someimplementations, multiple laser energy adjusting units 710 may includelenses or prisms of different light transmittances. Semiconductorstructure 702 may include a plurality of regions formed by a pluralityof materials, and one of a plurality of laser energy adjusting units 710may be moved to the first laser light path between splitter 720 andsemiconductor structure 702 based on the determination that first splitlaser beam 714 is focused on a preset region of semiconductor structure702.

For example, in some implementations, when the information stored in thedatabase or shown by the markings on semiconductor structure 702indicates that the material corresponding to a position 808 is aless-metal material, a first laser energy adjusting unit may be moved tothe first laser light path between splitter 720 and semiconductorstructure 702 to reduce the laser energy of first split laser beam 714.As a result, the first dicing energy irradiated on semiconductorstructure 702 at position 808 is a first laser energy.

In some implementations, when the information stored in the database orshown by the markings on semiconductor structure 702 indicates that thematerial corresponding to a position 810 is a more-metal material, laserenergy adjusting unit 710 may be moved away from the first laser lightpath between splitter 720 and semiconductor structure 702. As a result,the first dicing energy irradiated on semiconductor structure 702 atposition 810 is the original laser energy of first split laser beam 714without weakening and is a second laser energy higher than the firstlaser energy.

In some implementations, when the information stored in the database orshown by the markings on semiconductor structure 702 indicates that thematerial corresponding to a position 812 is a less-metal material, asecond laser energy adjusting unit may be moved to the first laser lightpath between splitter 720 and semiconductor structure 702 to reduce thelaser energy of first split laser beam 714. As a result, the firstdicing energy irradiated on semiconductor structure 702 at position 812is a third laser energy lower than the first laser energy.

Implementations of the present disclosure use the laser energy adjustingunit to change and control the final output laser beam energy irradiatedon the semiconductor structure, e.g., the wafer. The laser beam canchange the laser energy irradiated on the semiconductor structure at anytime during the laser dicing operation, therefore improves theconsistency of the laser grooving shape, and avoid the problems ofdifferent trench depths in different positions having differentmaterials.

FIG. 9 illustrates a flowchart of a method 900 for dicing a wafer,according to some aspects of the present disclosure. In operation 902, alaser energy adjusting unit is provided movably equipped on a laserlight path between the laser source and the wafer. The laser energyadjusting unit, e.g., laser energy adjusting unit 510 in FIG. 5, may bemovably provided on a laser light path between the laser source and thewafer. The laser energy adjusting unit is provided to reduce or weakenthe laser energy on the laser path.

In operation 904, a position of the laser energy adjusting unit ischanged to the laser light path or away from the laser light path basedon a determination of a material on the wafer along the cutting street.In some implementations, the materials of the wafer corresponding topositions along the cutting street may be pre-defined and stored in adatabase or a host device coupled to the laser system. In someimplementations, the materials of the wafer corresponding to positionsalong the cutting street may be pre-marked on the wafer, and the lasersystem may identify the markings. When the laser system moves along thecutting street to perform the laser dicing operation, one or more laserenergy adjusting unit may be optionally moved to the laser light pathbetween the laser source and the wafer according to the information ofthe materials of the wafer corresponding to positions along the cuttingstreet.

In operation 906, a trench is formed on the wafer by the laser sourcealong a cutting street. The output energy of the laser source maintainsthe same when dicing the wafer along the cutting street, and a dicingenergy irradiated on the wafer is adjustable when dicing the wafer alongthe cutting street.

In some implementations, the laser source may be split into a firstsplit laser source and a second split laser source. The first splitlaser source may generate a first dicing energy, and the first dicingenergy may be irradiated on the wafer along a first track in the cuttingstreet, and the second split laser source may generate a second dicingenergy, and the second dicing energy may be irradiated on the waferalong a second track in the cutting street parallel to the first track.The first dicing energy irradiated on the wafer along the first track isadjustable, and the second dicing energy irradiated on the wafer alongthe second track is fixed. The first dicing energy and the second dicingenergy are irradiated on the wafer simultaneously.

In operation 908, a mechanical is performed to cut the wafer along thecutting street having the trench formed by the laser source. Since thelaser energy adjusting unit is used to change and control the finaloutput laser beam energy irradiated on the wafer, the laser beam maychange the laser energy irradiated on the wafer at any time during thelaser dicing operation. Therefore, the consistency of the laser groovingshape is improved, and the problems of different trench depths indifferent positions having different materials are further prevented.

FIG. 10 illustrates a schematic diagram of a host device 1000, accordingto some implementations of the present disclosure. It is understood thathost device 1000 in the present disclosure may be an independent devicecoupled to the laser source and the laser energy adjusting unit. In someimplementations, host device 1000 may be located in the laser source. Insome implementations, host device 1000 may be located in the laserenergy adjusting unit. The location and connection relationship in FIG.10 is for illustration purpose only, not for limiting.

One or more host device 1000 can be cooperated with laser system 500 inFIG. 5 or laser system 700 in FIG. 7 to implement method 900 of FIG. 9.Host device 1000 may include one or more processors (also called centralprocessing units, or CPUs), such as a processor 1004. Processor 1004 isconnected to a communication infrastructure or bus 1006, according tosome implementations. One or more processors 1004 can each be a GPU. Insome implementations, a GPU is a processor that is a specializedelectronic circuit designed to process mathematically intensiveapplications. The GPU may have a parallel structure that is efficientfor parallel processing of large blocks of data, such as mathematicallyintensive data common to computer graphics applications, images, videos,etc.

Host device 1000 may also include user input/output device(s) 1003, suchas monitors, keyboards, pointing devices, etc., which communicate withcommunication infrastructure or bus 1006 through user input/outputinterface(s) 1002. Host device 1000 may also include a main or primarymemory 1008, such as random-access memory (RAM). Main memory 1008 caninclude one or more levels of cache. Main memory 1008 has stored thereincontrol logic (i.e., computer software) and/or data, according to someimplementations.

Host device 1000 may also include one or more secondary storage devicesor memory 1010. Secondary memory 1010 can include, for example, a harddisk drive 1012 and/or a removable storage device or drive 1014.Removable storage drive 1014 can be a floppy disk drive, a magnetic tapedrive, a compact disk drive, an optical storage device, tape backupdevice, and/or any other storage device/drive.

Removable storage drive 1014 can interact with a removable storage unit1018. Removable storage unit 1018 includes a computer usable or readablestorage device having stored thereon computer software (control logic)and/or data, according to some implementations. Removable storage unit1018 can be a floppy disk, magnetic tape, compact disk, DVD, opticalstorage disk, and/any other computer data storage device. Removablestorage drive 1014 can read from and/or writes to removable storage unit1018 in a well-known manner.

According to some implementations, secondary memory 1010 can includeother means, instrumentalities or other approaches for allowing computerprograms and/or other instructions and/or data to be accessed by hostdevice 1000. Such means, instrumentalities or other approaches mayinclude, for example, a removable storage unit 1022 and an interface1020. Examples of removable storage unit 1022 and interface 1020 caninclude a program cartridge and cartridge interface (such as that foundin video game devices), a removable memory chip (such as an EPROM orPROM) and associated socket, a memory stick and USB port, a memory cardand associated memory card slot, and/or any other removable storage unitand associated interface.

Host device 1100 may further include a communication or networkinterface 1024. Communication interface 1024 enables host device 1100 tocommunicate and interact with any combination of remote devices, remotenetworks, remote entities, etc. (individually and collectivelyreferenced by reference number 1028), according to some implementations.For example, communication interface 1024 may allow host device 1000 tocommunicate with remote devices 1028 over communications path 1026,which may be wired and/or wireless, and which may include anycombination of LANs, WANs, the Internet, etc. Control logic and/or datamay be transmitted to and from host device 1000 via communication path1026.

Further, communication interface 1024 enables host device 1100 tocommunicate a laser source 1050 and a laser energy adjusting unit 1052to control and coordinate the moving of laser energy adjusting unit 1052between laser source 1050 and the semiconductor structure. In someimplementations, host device 1000 may be an independent device coupledto laser source 1050 and laser energy adjusting unit 1052 throughcommunication interface 1024. In some implementations, host device 1000may be located in laser source 1050. In some implementations, hostdevice 1000 may be located in laser energy adjusting unit 1052.

In some implementations, laser energy adjusting unit 1052 may includecommunication interface 1024 to communicate with other device throughcommunication path 1026. For example, laser energy adjusting unit 1052may be coupled to laser source 1050, host device 1000 or other device toreceive a comment to move laser energy adjusting unit 1052 and performthe laser dicing operation.

According to one aspect of the present disclosure, a laser system fordicing a semiconductor structure is disclosed. The laser system includesa laser source and a laser energy adjusting unit. The laser source isconfigured to generate a laser. The laser energy adjusting unit ismovably provided on a laser light path between the laser source and thesemiconductor structure. The laser energy adjusting unit is moved to thelaser light path between the laser source and the semiconductorstructure based on a first determination that the laser source isfocused on a first preset region of the semiconductor structure having afirst material.

In some implementations, the laser energy adjusting unit is moved awayfrom the laser light path based on a second determination that the lasersource is focused on a second preset region of the semiconductorstructure having a second material. In some implementations, the firstpreset region and the second preset region are located along a cuttingstreet on the semiconductor structure. In some implementations, a firstdicing energy irradiated on the first preset region by the laser systemis lower than a second dicing energy irradiated on the second presetregion by the laser system. In some implementations, an output energy ofthe laser source maintains the same when dicing the semiconductorstructure along the cutting street.

In some implementations, a positioning unit is configured to move thelaser energy adjusting unit to the laser light path and move the laserenergy adjusting unit away from the laser light path. In someimplementations, the laser energy adjusting unit includes at least onefilter to reduce the first dicing energy irradiated on the first presetregion by the laser system. In some implementations, the at least onefilter reduces the first dicing energy to generate a gradienttransitional dicing energy. In some implementations, the laser energyadjusting unit has an additional laser light path, and the additionallaser light path and the laser light path are combinedly providedbetween the laser source and the semiconductor structure. In someimplementations, the laser energy adjusting unit includes a shelter toreduce the first dicing energy irradiated on the first preset region bythe laser system.

In some implementations, a focusing unit is deposited between the laserenergy adjusting unit and the semiconductor structure to focus the firstdicing energy irradiated on the first preset region. In someimplementations, a focusing unit is deposited between the laser sourceand the semiconductor structure to focus the second dicing energyirradiated on the second preset region.

According to another aspect of the present disclosure, a laser systemfor dicing a semiconductor structure is disclosed. The laser systemincludes a laser source, a splitter and a laser energy adjusting unit.The laser source is configured to generate a laser. The splitter splitsthe laser source into a plurality of split laser sources, and theplurality of split laser sources include a first split laser source anda second split laser source. The laser energy adjusting unit is movablyprovided on a first laser light path between the first split lasersource and the semiconductor structure. The first split laser sourcegenerates a first dicing energy irradiated on the semiconductorstructure along a first track, the second split laser source generates asecond dicing energy irradiated on the semiconductor structure along asecond track parallel to the first track, and the first track and thesecond track are located in a cutting street. The first dicing energyirradiated on the semiconductor structure along the first track isadjustable.

In some implementations, the first dicing energy and the second dicingenergy are irradiated on the semiconductor structure simultaneously. Insome implementations, the second dicing energy irradiated on thesemiconductor structure along the second track is fixed. In someimplementations, the laser energy adjusting unit is moved to the firstlaser light path between the first split laser source and thesemiconductor structure based on a first determination that the firstsplit laser source is focused on a first preset region of thesemiconductor structure having a first material.

In some implementations, the laser energy adjusting unit is moved awayfrom the first laser light path between the first split laser source andthe semiconductor structure based on a second determination that thefirst split laser source is focused on a second preset region of thesemiconductor structure having a second material. In someimplementations, the first dicing energy irradiated on the first presetregion by the first split laser source is lower than the first dicingenergy irradiated on the second preset region by the first split lasersource. In some implementations, a positioning unit is configured tomove the laser energy adjusting unit to the first laser light path andmove the laser energy adjusting unit away from the first laser lightpath.

In some implementations, the laser energy adjusting unit includes atleast one filter to reduce the first dicing energy irradiated on thefirst preset region by the first split laser source. In someimplementations, the at least one filter reduces the first dicing energyto generate a gradient transitional dicing energy. In someimplementations, the laser energy adjusting unit has an additional laserlight path, and the additional laser light path and the first laserlight path are combinedly provided between the first split laser sourceand the semiconductor structure. In some implementations, the laserenergy adjusting unit includes a shelter to reduce the first dicingenergy irradiated on the first preset region by the first split lasersource.

In some implementations, a focusing unit is deposited between the laserenergy adjusting unit and the semiconductor structure to focus the firstdicing energy irradiated on the first preset region. In someimplementations, a focusing unit is deposited between the first splitlaser source and the semiconductor structure to focus the first dicingenergy irradiated on the second preset region.

According to still another aspect of the present disclosure, a methodfor dicing a wafer is disclosed. A trench is formed on the wafer by alaser source along a cutting street. An output energy of the lasersource maintains the same when dicing the wafer along the cuttingstreet, and a dicing energy irradiated on the wafer is adjustable whendicing the wafer along the cutting street. A mechanical cutting isperformed on the wafer along the cutting street having the trench formedby the laser source.

In some implementations, a laser energy adjusting unit is providedmovably equipped on a laser light path between the laser source and thewafer, and a position of the laser energy adjusting unit is changed tothe laser light path or away from the laser light path based on adetermination of a material on the wafer along the cutting street.

In some implementations, the laser source is split into a plurality ofsplit laser sources, and the plurality of split laser sources include afirst split laser source and a second split laser source. A first dicingenergy generated by the first split laser source is irradiated on thewafer along a first track in the cutting street, and a second dicingenergy generated by the second split laser source is irradiated on thewafer along a second track in the cutting street parallel to the firsttrack.

In some implementations, the first dicing energy irradiated on the waferalong the first track is adjustable, and the second dicing energyirradiated on the wafer along the second track is fixed. In someimplementations, the first dicing energy and the second dicing energyare irradiated on the wafer simultaneously.

The foregoing description of the specific implementations can be readilymodified and/or adapted for various applications. Therefore, suchadaptations and modifications are intended to be within the meaning andrange of equivalents of the disclosed implementations, based on theteaching and guidance presented herein.

The breadth and scope of the present disclosure should not be limited byany of the above-described exemplary implementations, but should bedefined only in accordance with the following claims and theirequivalents.

What is claimed is:
 1. A laser system for dicing a semiconductorstructure, comprising: a laser source configured to generate laser; anda laser energy adjusting unit movably provided on a laser light pathbetween the laser source and the semiconductor structure, wherein thelaser energy adjusting unit is moved to the laser light path between thelaser source and the semiconductor structure based on a firstdetermination that the laser source is focused on a first preset regionof the semiconductor structure having a first material.
 2. The lasersystem of claim 1, wherein the laser energy adjusting unit is moved awayfrom the laser light path based on a second determination that the lasersource is focused on a second preset region of the semiconductorstructure having a second material.
 3. The laser system of claim 2,wherein the first preset region and the second preset region are locatedalong a cutting street on the semiconductor structure.
 4. The lasersystem of claim 3, wherein a first dicing energy irradiated on the firstpreset region by the laser system is lower than a second dicing energyirradiated on the second preset region by the laser system.
 5. The lasersystem of claim 3, wherein an output energy of the laser sourcemaintains the same when dicing the semiconductor structure along thecutting street.
 6. The laser system of claim 1, further comprising: apositioning unit configured to move the laser energy adjusting unit tothe laser light path and move the laser energy adjusting unit away fromthe laser light path.
 7. The laser system of claim 1, wherein the laserenergy adjusting unit comprises at least one filter to reduce the firstdicing energy irradiated on the first preset region by the laser system.8. The laser system of claim 7, wherein the at least one filter reducesthe first dicing energy to generate a gradient transitional dicingenergy.
 9. The laser system of claim 1, wherein the laser energyadjusting unit has an additional laser light path, and the additionallaser light path and the laser light path are combinedly providedbetween the laser source and the semiconductor structure.
 10. The lasersystem of claim 1, wherein the laser energy adjusting unit comprises ashelter to reduce the first dicing energy irradiated on the first presetregion by the laser system.
 11. The laser system of claim 1, furthercomprising: a focusing unit deposited between the laser energy adjustingunit and the semiconductor structure to focus the first dicing energyirradiated on the first preset region.
 12. The laser system of claim 1,further comprising: a focusing unit deposited between the laser sourceand the semiconductor structure to focus the second dicing energyirradiated on the second preset region.
 13. A laser system for dicing asemiconductor structure, comprising: a laser source configured togenerate laser; a splitter to split the laser source into a plurality ofsplit laser sources, the plurality of split laser sources comprising afirst split laser source and a second split laser source; and a laserenergy adjusting unit movably provided on a first laser light pathbetween the first split laser source and the semiconductor structure,wherein the first split laser source generates a first dicing energyirradiated on the semiconductor structure along a first track, thesecond split laser source generates a second dicing energy irradiated onthe semiconductor structure along a second track parallel to the firsttrack, and the first track and the second track are located in a cuttingstreet; and wherein the first dicing energy irradiated on thesemiconductor structure along the first track is adjustable.
 14. Thelaser system of claim 13, wherein the first dicing energy and the seconddicing energy are irradiated on the semiconductor structuresimultaneously.
 15. The laser system of claim 13, wherein the laserenergy adjusting unit is moved to the first laser light path between thefirst split laser source and the semiconductor structure based on afirst determination that the first split laser source is focused on afirst preset region of the semiconductor structure having a firstmaterial.
 16. A method for dicing a wafer, comprising: forming a trenchon the wafer by a laser source along a cutting street, wherein an outputenergy of the laser source maintains the same when dicing the waferalong the cutting street, and a dicing energy irradiated on the wafer isadjustable when dicing the wafer along the cutting street; andperforming a mechanical cutting on the wafer along the cutting streethaving the trench formed by the laser source.
 17. The method of claim16, wherein forming the trench on the wafer by the laser source alongthe cutting street, comprises: providing a laser energy adjusting unitmovably equipped on a laser light path between the laser source and thewafer; and changing a position of the laser energy adjusting unit to thelaser light path or away from the laser light path based on adetermination of a material on the wafer along the cutting street. 18.The method of claim 16, further comprising: splitting the laser sourceinto a plurality of split laser sources, the plurality of split lasersources comprising a first split laser source and a second split lasersource; irradiating a first dicing energy generated by the first splitlaser source on the wafer along a first track in the cutting street; andirradiating a second dicing energy generated by the second split lasersource on the wafer along a second track in the cutting street parallelto the first track.
 19. The method of claim 18, wherein the first dicingenergy irradiated on the wafer along the first track is adjustable, andthe second dicing energy irradiated on the wafer along the second trackis fixed.
 20. The method of claim 19, wherein the first dicing energyand the second dicing energy are irradiated on the wafer simultaneously.